2021-05-25 19:55:06 +10:00
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/** \page page_design PipeWire Design
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2015-08-21 11:46:29 +02:00
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2017-06-21 13:17:43 +02:00
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PipeWire is a media server that can run graphs of multimedia nodes.
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Nodes can run inside the server or in separate processes.
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2015-08-21 11:46:29 +02:00
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Some of the requirements are:
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2017-06-21 13:17:43 +02:00
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- must be efficient for raw video using fd passing and audio with
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shared ringbuffers
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2016-05-09 12:16:04 +02:00
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- must be able to provide/consume/process media from any process
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2015-08-21 11:46:29 +02:00
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- policy to restrict access to devices and streams
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2017-06-21 13:17:43 +02:00
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- extensible
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2015-08-21 11:46:29 +02:00
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Although an initial goal, the design is not limited to raw video
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only and should be able to handle compressed video and other
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2017-06-21 13:17:43 +02:00
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media as well.
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2015-08-21 11:46:29 +02:00
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2017-06-21 13:17:43 +02:00
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PipeWire uses the SPA plugin API for the nodes in the graph. SPA is
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a plugin API designed for low-latency and efficient processing of
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any multimedia format.
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Some of the application we intend to build
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- v4l2 device provider. Provide controlled access to v4l2 devices
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and share 1 device between multiple processes.
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- gnome-shell video provider. Gnome-shell provides a node that
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gives the contents of the frame buffer for screen sharing or
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screen recording.
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- audio server. Mix and playback multiple audio streams. The design
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is more like CRAS (Chromium audio server) than pulseaudio and with
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the added benefit that processing can be arranged in a graph.
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- Pro audio graph processing like JACK.
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- Media playback backend
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2015-08-21 11:46:29 +02:00
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2017-01-19 18:10:00 +01:00
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Protocol
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--------
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2016-05-05 13:31:18 +02:00
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2017-06-21 13:17:43 +02:00
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The native protocol and object model is similar to wayland but with custom
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2017-01-19 18:10:00 +01:00
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serialization/deserialization of messages. This is because the datastructures
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2020-07-22 20:54:06 +02:00
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in the messages are more complicated and not easily expressible in xml format.
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2015-08-21 11:46:29 +02:00
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2017-06-21 13:17:43 +02:00
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Extensibility
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2015-12-04 16:39:29 +01:00
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-------------
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2017-06-21 13:17:43 +02:00
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The functionality of the server is implemented and extended with modules and
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extensions. Modules are server side bits of logic that hook into various
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places to provide extra features. This mostly means controlling the processing
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graph in some way.
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Extensions are the client side version of the modules. Most extensions provide
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both a client side and server side init function. New interfaces or new object
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implementation can easily be added with modules/extensions.
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Some of the extensions that can be written
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- protocol extensions: a client/server side API (.h) together with protocol
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extensions and server/client side logic to implement a new object or
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interface.
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- a module to check security of method calls
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- a module to automatically create or link or relink nodes
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2016-07-28 21:19:20 +02:00
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2017-06-21 13:17:43 +02:00
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- a module to suspend idle nodes
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2021-05-25 19:55:06 +10:00
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*/
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